Telescopium telescopium, commonly known as the telescope snail, is a species of snail in the horn snail family Potamididae found in mangrove habitats in the Indo-Pacific. They are large snails that can grow up to in length and are easily recognizable by their cone-shaped shell. Telescope snails are edible and are eaten in parts of Southeast Asia. They are known locally as bagongon or bagungon in the Philippines; and rodong or berongan in Malaysia, Singapore, and Indonesia. Description Telescopium telescopium are very similar in description to many other Potamidiae gastropods with the main points of difference being it being the largest in the family and the fold on its columella. Telescopium telescopium are relatively large in comparison to other molluscs in the Potamidiae family having a shell that ranges from 8–13 cm when fully grown. The shell is thick and heavy relative to the snail itself. The opening of the shell is perpendicular to the shell’s longitudinal axis, creating the straight sided cone shape. The shell of Telescopium telescopium differs from most other gastropods because it contains 0.12% magnesium carbonate. The operculum is rigiclaudent, meaning that the last growth increment always lies tangentially against the labial lip of the previous whorl. This makes it an exception within the family Potamididae, where the opercula of the shells are flexicaudent. Telescopium telescopium shells are either black or very dark reddish brown. They also have a fold on the columella of their shells, which makes them the only gastropod in the Potamidiae family to have so. Despite the obvious colour of the shell they are often covered in barnacles and mud obscuring the natural colour of the it. Telescopium telescopium outside of the shell have a black exterior with a long proboscis. It also has three eyes, one on its shell boundary and two near its proboscis protrusion. Telescopium telescopium respiratory system works in the same way to other semi-tidal gastropods in that it gets oxygen from water passing over small gills located on the inside of its shell. When the tide goes back out, the Telescopium telescopium will withdraw into its shell, reserving energy and oxygen until the ebb tide phase returns where they become active again. Telescopium telescopium are able to store saved oxygen for at least 36 hours and up to 48 hours before dying. Telescopium telescopium digestive system starts at its proboscis. It uses this to collect nutrient rich